The invention relates to instrumentation and, more particularly, to instruments for displaying measurements from data that is available on a vehicle or equipment data bus.
Instruments are used to indicate various measurements during the operation of an apparatus such as a vehicle or other machinery. The instruments may be used for indicating pressure, temperature, liquid level, rotations per minute (RPM) and various other measurements that are monitored during the operation of the apparatus. These instruments are well known in the art and are supplied in several varieties including analog and digital gauges. The analog gauges typically operate using an analog signal emanating from a sensor or sender that drives a needle on the gauge to indicate the measurement. The digital gauges are typically driven by signals emanating from a sender or sensor that have passed through an analog to digital conversion in order to supply a digital signal to the gauge.
The digital signals produced from the analog to digital conversion may also be applied to an onboard data bus. In a vehicle, for example, the onboard data bus serves to provide data to microprocessors connected to the data bus for monitoring vehicle performance. In addition to monitoring, the microprocessors connected to the onboard data bus are capable of adjusting various parameters in order to enhance the vehicle performance. In addition to providing monitoring for controlling and adjusting the vehicle performance, the onboard data bus has also been used to display selected measurements to an operator of the vehicle. A typical architecture for such a system includes a central controller that is a stand alone component connected to the onboard vehicle data bus. The central controller includes a plurality of outputs each for driving a selected instrument. The central controller gathers data from the onboard data bus and outputs either digital or analog signals to drive each instrument. While it is desirable to utilize the onboard data bus for driving instruments such as gauges, it is also desirable to minimize the number of components in the architecture. It is further desirable to maintain the power consumption of the system at minimum levels.
It is therefore an object of the present invention to provide a system and components wherein each instrument is connectable directly to a vehicle data bus without the need for a central controller while maintaining power consumption at a minimum. The system and method according to the present invention displays monitored measurements of an apparatus on an instrument and includes a data bus interface, a data bus, and a plurality of instruments. The data bus interface is coupled to a data bus of the apparatus, which contains measurement data monitored by sensors in the apparatus. Each of the instruments has a microcontroller coupled to the data bus interface. A motor is driven by the microcontroller and an indicator needle is coupled to the motor for displaying the measurement of the instrument.